Identification of Imipenem and Fosfomycin Resistance Genes in Enterobacter cloacae from Various Samples at a Tertiary Care Hospital in Bangladesh

Abstract

Background: Enterobacter cloacae is a significant pathogen that has been isolated from numerous clinical infections. Multidrug resistant (MDR) E. cloacae strains are increasing worldwide and limiting therapeutic options. This study’s objective was to detect the fosfomycin and imipenem resistance genes among E. cloacae isolated from the patients of a tertiary care hospital in Bangladesh.

Materials and Methods: This was a descriptive observational study conducted in the department of Microbiology, Dhaka Medical College, in collaboration with in-patient departments of Dhaka Medical College Hospital (DMCH) from January 2022 to December 2022. A total of 382 patients of different age and sex was selected by purposive sampling for this study. Wound swabs and pus, urine, blood and endotracheal aspirate were collected from the selected patients.The antimicrobial resistance pattern was determined for all isolated E. cloacae strains by disc diffusion method. Imipenem resistance gene (blaKPC) and fosfomycin resistance genes (fosA3 and fosC2) were detected by PCR using specific primers from Fosfomycin resistant and Imipenem resistant E. cloacae strain.

Results: Among 382 samples, 247 (64.66%) were culture positive. Organisms were isolated and identified by culture, gram staining, and biochemical tests, of which 31 isolates were E. cloacae. Most of the isolates showed resistance to β-lactam inhibitors, the extended spectrum of cephalosporins, fluoroquinolones, amikacin, gentamicin, and carbapenems. However, the least resistant drug was tigecycline (35.48%). The imipenem resistance gene blaKPC was detected in 7 out of 22 imipenem-resistant E. cloacae isolates (31.82%). Additionally, fosfomycin resistance genes fosA3 and fosC2 were identified in 6 (30%) and 2 (10%) isolates, respectively, among the 20 fosfomycin-resistant E. cloacae samples.

Conclusion: There is an ongoing need for surveillance programs to develop effective treatment strategies to combat antimicrobial resistance (AMR). It is essential to understand the prevalence of these resistance genes and the underlying factors contributing to their emergence to mitigate the burden of AMR.

Eastern Med Coll J. July 2025; 10 (2): 84-88